“Climate Change: what do we know about the IPCC?”

Summary: Here’s an excellent summary of the large body of research about the UN’s Intergovernmental Panel on Climate Change (IPCC), which has become a major player in public policy.

Recommended reading: “Climate Change: what do we know about the IPCC?“, Mike Hulme and Martin Mahony (School of Environmental Sciences, U of East Anglia), Progress in Physical Geography (a highly rated, peer-reviewed journal), in press

Conclusions

It represents a narrow range of disciplinary expertise.

It represents a narrow range of the world’s nations, with aprox 80% of authors and reviews from the OECD. As Bert Bolin, the then chairmen of the IPCC remarked back in 1991: “Right now, many countries, especially developing countries, simply do not trust assessments in which their scientists and policymakers have not participated. Don’t you think credibility demands global representation?”

It poorly describes the certainties and uncertainties in our knowledge. It provides an illusion of consensus.

The last is perhaps most important, described in this excerpt from pp 10-11.

Consensus and Uncertainty

Since its origins, the IPCC has been open and explicit about seeking to generate a ‘scientific consensus’ around climate change and especially about the role of humans in climate change. Yet this has been a source of both strength and vulnerability for the IPCC.

… Consensus-building in fact serves several different goals. As Horst and Irwin (2010) have explained, seeking consensus can be as much about building a community identity – what Haas (1992) refers to as an epistemic community – as it is about seeking the ‘truth’. Equally, as Yearley (2009) explains, IPCC consensus-making is an exercise in collective judgement about subjective (or Bayesian) likelihoods in areas of uncertain knowledge. Consensus-making in the IPCC has been largely driven by the desire to communicate climate science coherently to a wide spectrum of policy users – ‘to construct knowledge’ (Weingart, 1999) – but in so doing communicating uncertainties have been down-played (van der Sluijs, 1998). As Oppenheimer et al. (2007: 1506) remark: “The establishment of consensus by the IPCC is no longer as critical to governments as [is] a full exploration of uncertainty.”

Without a careful explanation about what it means, this drive for consensus can leave the IPCC vulnerable to outside criticism. Claims such as ‘2,500 of the world’s leading scientists have reached a consensus that human activities are having a significant influence on the climate’ are disingenuous. That particular consensus judgement, as are many others in the IPCC reports, is reached by only a few dozen experts in the specific field of detection and attribution studies; other IPCC authors are experts in other fields.

About the author

Mike Hulme is a Professor of Climate Change in the School of Environmental Sciences at the University of East Anglia (UEA). His work explores climate change using historical, cultural and scientific analyses, seeking to illuminate the numerous ways in which climate change is deployed in public and political discourse. He was the founding Director (2000-2007) of the Tyndall Centre for Climate Change Research. A longer bio and full CV – including a statement of my financial interests and research funders – can be found here, along with a personal statement about climate change. (source; also see the Wikipedia entry about him)

For more information about the IPCC

For more about the IPCC distortions of the science about climate impacts on natural disasters, see these posts on the website of Roger Pielke Jr: